It has been realized for quite some time that the muscles of a human or other animal are normally caused to contract in response to electrical signals generated in the body and that externally generated electrical signals can be applied to muscle tissue to induce contraction thereof. This phenomenon is familiar to students of biology in experiments following dissection, and the technique, broadly has been employed with cardiac muscle tissue and in other ways as illustrated by the following issued U.S. Pat. Nos.
3,472,233 Sarbacher; PA1 3,566,877 Smith et al; PA1 3,628,538 Vincent et al; PA1 3,773,051 Holcomb et al; PA1 3,881,496 Vredenbregt et al; PA1 3,946,745 Hsiang-Lai et al; PA1 3,978,864 Smith et al; PA1 3,983,881 Wickham; PA1 4,019,518 Maurer et al; PA1 4,071,033 Nawracaj et al;
As recognized in Sarbacher, electrical pulses can be applied through electrode pads applied to the skin to stimulate muscle activity, and others of the above patents relate to implants and other forms of applying electrical energy to the body.